[ntp:questions] NTPD 4 hours off date problem
xbntp at mailinator.com
Tue May 10 08:37:28 UTC 2005
Brad Knowles a écrit :
> At 3:45 PM +0200 2005-05-09, X.B. wrote:
>> The computer i'm using has no cmos battery, so each time it is cold
>> rebooted, the internal clock is set to something around 01-01-2000.
>> In this case, ntpd -g -q cannot set up the date correctly.
>> Nor can ntpd -g ...
> There is a 1000 second sanity check, and if you're outside of that
> then ntpd will refuse to start. However, this can be over-ridden with
> the "-g" option. At that point, you should be able to use ntpd to sync
> your time regardless of how far off your system clock is.
> If that's not working, I think you've got much more serious problems.
>> I've gone through the source code, and found that antenna's NTP packets
>> are thrown out (1) because the date they contain is more than 4 hours
>> (CLOSETIME 4*60*60) off the system date ... So ntpd refuse to set the
> Precisely where in the code are you seeing this?
The check on received packet ( if i understand correctly ... ) is made
In my case, clocktime() is called from ntp_refclock.c:refclock_process()
on line 439 calls.
As said upper, ntpd cannot work as the packets seems to be thrown out
before even the 1000s sanity check is done. That's why -g and -q are of
About other responses : Thanks for you all !
From what i read from your ( fast! ) responses
i'll need to make a hack, in or out of ntp, to force the clock somewhere.
I this case, using the CMOS clock is not an option ( i know, i know ...
), nor using a file date ( i cannot know how long the computer will be
powered off, and due to the +-4 hours validity range ...
I'm not sure if it is a good idea, but what about suppressing the test
against CLOSETIME from clocktime when '-g' option is set
that is, extending the 'effect' of the -g option to clocktime :
- 1st packet check do NOT check against CLOSETIME.
- Following packets are fully checked
Or may be ignoring colcktime errors from caller(s) when -g is used
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